The pathology core, consisting of four pathology faculty and a staff of assistants, serves all of the program projects by providing anatomic pathology data collection and extensive professional anatomic pathology and other diagnostic consultative analysis. This core manages the collection, logging, storage, processing and analysis of biological tissue specimens and their identifying data and tracking for this grant. The unit coordinates all tissue specimen related data collection and distribution to pathology and other Fred Hutchinson Cancer Research Center (FHCRC) research laboratories. Bone marrow, for example, is divided into specimens for hematology, pathology, cytogenetics, flow cytometry, and other laboratories. Long-term follow-up specimens are seen by the uniquely experienced pathology staff whether billing is collectable or not. Processing includes freezing, fixation, embedding, storage, and appropriate distribution to a subset of intramural FHCRC laboratories. Analytic methods available within pathology include research immunohistochemistry, in situ hybridization (as for Y chromosome DNA), polymerase chain reaction (PCR), fluorescence in situ hybridization (FISH), and specialized graft- versus-host disease (GVHD) studies (e.g., Tunel stain for apoptosis) in human and canine marrow graft recipients. Research and development of new methodology in automated immunohistochemistry, in situ hybridization, and PCR provide "cutting edge" technology to support the studies of the research projects within the program project. Research in the pathogenesis and diagnosis of the diseases of bone marrow transplantation, such as graft-versus-host disease, venocclusive disease and other toxicity, infectious disease, and molecular diagnostics, also support the program's individual projects and the program as a whole.